Preheat oven to 400 degrees
Line baking sheet with parchment paper
In a food processer, combine flour, xantham gum, baking powder, salt, and sugar - mix until blended (if you don't have a food processor you can do this by hand)
Add the sliced chilled butter into the food processor and pulse until combined
Pour the milk in the processor and mix until dough forms
Move the dough into a bowl and fold in the berries
Gently form triangles of dough onto the sheet pan - 8-10 scones
Sprinkle the tops with sugar and put in the oven
Bake for 15-20 minutes